SOUTH African state power firm Eskom loses well over 1 billion rands ($55 million) a month from theft, its former chief executive told parliament, saying a previous estimate he gave was conservative. Andre de Ruyter made the comments in a written submission to parliament's Standing Committee on Public Accounts (SCOPA) seen by Reuters, following an interview to local news channel eNCA in February where he made sweeping corruption allegations without detailed evidence against Eskom and South Africa's governing African National Congress. Shortly after the interview aired Eskom announced de Ruyter would leave his job immediately, cutting short a notice period he was serving after…